| Lien | https://sciences.ucf.edu/physics/atto/wp-content/uploads/sites/28/2022/06/ATTOVIII_BOA_June21.pdf |
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| Auteur | Rechercher : Endo, T.; Rechercher : Neville, S. P.1; Rechercher : Lassonde, P.; Rechercher : Qu, C.; Rechercher : Fujise, H.; Rechercher : Fushitani, M.; Rechercher : Hishikawa, A.; Rechercher : Houston, P. L.; Rechercher : Bowman, J. M.; Rechercher : Schuurman, M. S.1; Rechercher : Légaré, F.; Rechercher : Ibrahim, H. |
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| Affiliation | - Conseil national de recherches du Canada. Technologies de sécurité et de rupture
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| Format | Texte, Résumé |
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| Conférence | 8th International Conference on Attosecond and Technology, July 11-15, 2022, Orlando, FL, USA |
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| Résumé | As a photoexcited molecule breaks apart, we can see fragments following the direct dissociation path, as well as fragments deviating from this minimum energy path. So-called roaming fragments explore the potential energy landscape in a statistical manner and are directly captured using Coulomb explosion imaging (CEI). Individual pathways are distinguished based on state-of-the-art theory analysis.
How to image statistical dynamics of individual reaction pathways hidden in an overwhelming background? We made use of the capability of CEI to detect the ion-breakup of single-molecules in real time. We investigated the uni-molecular dissociation reactions in the deuterated formaldehyde molecule (D₂CO). In addition to the conventional dissociation channels – molecular and radical dissociation – a third channel termed roaming has been discovered in 2004, which bypasses the transition state. Identified through spectroscopic footprints using high-resolution spectroscopy and found in a variety of molecules, roaming fragments had however never been observed directly and in a time-resolved way. We succeeded in doing so by using the highly sensitive CEI method in combination with high-level first-principles simulations of all critical experimental steps. Distinctive roaming signatures were identified in the experimental data (see Fig. 1). These were rendered observable by extracting rare stochastic events out of an overwhelming background. Additionally, this first identification of transient roaming features allowed to generalize the definition of roaming. While it was previously assumed that roaming results in molecular dissociation only, we observed that roaming might also be followed by radical dissociation. We further investigated how the overall dissociation depends on the employed UV pump wavelength. |
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| Date de publication | 2022-07-11 |
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| Maison d’édition | The Conference |
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| Dans | |
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| Langue | anglais |
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| Exporter la notice | Exporter en format RIS |
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| Signaler une correction | Signaler une correction (s'ouvre dans un nouvel onglet) |
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| Identificateur de l’enregistrement | 312b9c5d-33b6-4a82-aec9-b75aa615d314 |
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| Enregistrement créé | 2023-05-04 |
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| Enregistrement modifié | 2023-05-05 |
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